PORTLAND, Maine 
A lawyer for the Maine Democratic Party and other groups says they had a constitutional right to challenge Ralph Nader's efforts to get on ballots in the 2004 presidential election.

He argued before Maine supreme court justices Wednesday in the latest development in Nader's 2009 lawsuit against the party and allied organizations. Nader's attorney told the justices that the party can't make baseless allegations to block a candidate from the ballot.

Nader claims the party, the Democratic National Committee and other groups used illegal and malicious tactics to try to keep him off the ballot in Maine and more than a dozen other states in his run for president.

The party is appealing a lower court's ruling that allowed Nader's lawsuit to proceed.